Apparently the Lego Indiana Jones game will be released for PC, but I'm curious why the other yet-to-titled Indy game is only coming out for the three consoles. Is there something about the "Euphoria" design that won't work on PC?

Just like with DF3 and TFU they want only to release it on consoles to serve a bigger general audience. Since this game is going to be next gen they want it to be on a next gen console. They aren't going to bother with porting it to PC until the sales are high enough.